Method of superficially finishing rubber articles



'5'. D. SHINKLE METHOD OF SUPERFICIALLY FINISHING RUBBER ARTICLES Original Filed Dec. 13, 1926 Oct. 27, 1 931.

nvemtoz SEEP/1E5 0. 5111mm:

Patented a. 27, 1931 UNITE!) 'S'I'IATES PATENT OFFICE BEAPHES D. SHINKLE, OF NEW HAVEN, CONNECTICUT, .ASSIGNOB TO L. CANDEE'& GOM- PANY, OF NEW HAVEN, CONNECTICUT, A CORPORATION OI CONNECTICUT mn'rnon or sorn'ancmL Y rm'rsnme RUBBER narrows Application m December 1a, 1926. Serial 110. 154,019.

' This invention relates to a method of superficially finishing rubber articles, and the product thereof, more particularly as applied to the finishing of rubber footwear art cles. This case is a continuation in part of application Serial No. 80,971, filed January 13, 1926.

Ordinary soft cured rubber articles which have been vulcanized in open heat have a semi-gloss finish that is easily marked, while in the case of certain articles such as rubber footwear, hand baggage, etc., a large part of the trade demands a glossy finish. To roduce such a finish, articles such as ru ber footwear, etc., have usually been varnished before vulcanization with a vulcanizable varnish, this varnish ordinarily consisting of an oxidizable or drying oil, such as linseed, compounded with sulphur and other materials such as rosin, gilsonite, etc., the specific proportions and ingredients varying somewhat with difli'erent manufacturers. The articles, after coating with such a varnish and vulcanization acquire a high loss. However, the finish is quite soft an tacky after removal from the vulcanizing oven, so that it is impossible to immediately wrap the goods in paper and pack them, since the paper tends to stick to the goods. This necessitates a further drying or treatment in the open air to remove the tackiness before the goodscan be packed, with resulting loss of time and use of valuable factory space. Moreover while the air treatment will. remove the tackiness sufliciently to enable the goods to be handled and packed, it persists in some degree for a considerable length of time, and certain branches of the trade object to this condition and, desire goods having a relatively'hard, smooth and non-tacky finish when received.

An object of my invention is to provide an,

improved method for superficially finishing rubber articles. Another object is to provide a method for immediately. removing the ject is to speed up the production of varmsh'ed rubber articles such as footwear.

W1thout intention to limit the invention otherwlse than as required by the prior art the method consists broadly in subjecting varnlshed rubber articles to both vulcanizat1on and a superficial treatment with a halogen or halide of one of the sulphur group such as sulphur or selenium in gaseous form, elther of these operations being performed first. It further consists in first applying to the article a varnish embodying an oxidizable or d ying oil, vulcanizing the article, and giving the varnish a-superficial treatment with a sulphur chloride. The invention also comprises the product of the method.

For a detailed disclosure of the nature and objects of the invention reference is had to,

the accompanying specification and drawing, in which latter:

The fi ure is a front elevation of a suitable form 0 Referring to the drawing, the numeral 1 one branch of the latter a pipe 4 extends some distance into a receptacle 5 for the treating agent, so as to bubble up through the latter and become charged with it. The treating agent may be sulphur mono or dichloride, chlorine, bromine, sulphurylchloride, thionylchloride, or seleniumoxychloride. As chlorine is a gas at ordinary temperatures and pressures, the charging apparatus 4 is of course unnecessa when using chlorine, and

. the gas may. be dlrectly mixed with the air..-

Leading from the rece tacle 5 is a pipe 6 governed by a valve 6'- ?or conducting away the air or other gaseous fluid charged with the treating agent. Also connected to the three-way valve 3 is a pipe 7 extending into a receptacle 8 containing ammonia or other base capable of neutralizing the treating agent, in a manner to be hereinafter depum treating gases -in the chamber 1 is obtained.-

scribed. Leadin from the receptacle 8 is a pipe 9 governed y a valve 9' for conductin away air or other gaseous fluid charged with the ammonia or other neutralizing material used. A circulating ump 10 has its discharge outlet connecte to a ipe 11 leading into the top of chamber 1 an the respective pipes 6 and 9 are tapped into the pipe 11, while the inlet of the pump 10 is connected b a pipe 12 to the bottom portion of the cfi amber 1. Leading from the chamber 1 is a pipe 13 connected to an exhaust pump 14 for exhaustin the gases from the chamber 1 when desir a In carrying out one form of the method rubber articles, for instance rubber footwear, are dipped, sprayed or otherwise coated with the usual varnish embodying-an oxidizable or drying oil and sulphur, the oil most commonly used being boiled linseed oil. The articles may be then placed in the. vulcanizer and cured as usual. On removal the articles have a bright glossy finish, but the surface of the varnish is soft and quite tacky, and in this condition can be easily marked or defaced. The surface treatment of the articles may be accomplished at any later period, but it is preferred to take the articles while still warm after vulcanization and place them in the chamber 1. The valve 3 is then turned to admit compressed air into the receptacle 5 and this air char ed with the treating agent, preferably sulp ur monochloride, is conducted through the pipe 6 and then through the pipe 11 into the chamber 1. By means of the 10,- a continuous circulation of the The concentration of the sulphur monochloride in the air or other carrying fluid is preferably kept rather low. The action of V the treating a ent if in any great strength or if applied or any length of time is 111- jurious to the linings or other' fabric parts of the rubber articles being'treated, and to obviate such injury, as soon as the surface treatment of the article has continued longenough to obtain the desired effect the threeway valve 3 is turned to cut off the flow of the air.or other carrier medium into the receptacle 5, and the air is instead diverted into the receptacle 8 and thence through pipes 9 and 11. This causes the introduction into the.

chamber 1 of air or other carrier medium imregnated with ammonia or other neutralizmg agent for the treating medium. After sufficient time has elapsed to insure the complete neutralization of any-excess sulphur chloride the valve 3 is turned to cut off the fll 1 w of compressed air into receptacle 8, and t e chamber 1 by the pump 14 and the chamber opened and the articles removed.

In order to economize on the use of ammonia, it is preferred after the treatment with the sulphur'chloride' or other treating gases may then be exhausted from the the halogen, sulphur chlorideor other treating agent, 2 to t minutes exhausting unused gas from the chamber, to 2 minutes treat-' ment with the neutralizing base, and 2 "to 4 minutes exhausting before removal, of the articles from the chamber.

As a modification of the above described method the varnished articles may be first treated with the halogen or sulphur halide and then vulcanized. When the method, is carried outin this manner the action of the halogen or sulphur halide is to first produce a relatively thin hardened film on the varnish, I

and when the article is later vulcanized this film contracts so as to 've the vulcanized article a finely crinkle or puckered but glossy surface. This crinkled surface has an ornamental appearance which is desirable in the case of certain classes of goods, such as auto topping and other sheet materials, childrens rubber footwear, etc.

By the use of my invention the tacky feel of varnished rubber articles maybe entirely removed and the varnish given a glossy, last-' b g surface which is strongly resistant to abrasion; cracking or marking. It produces an article which has been entirely freed from tackiness in a short time and which consetreatment. An article finis ed in this manner when newly received shall have a hard glossy surface free "from tackiness.

The expression halide of a metalloid is to be contemplated broadly as including the halides mentioned herein or their equivalents.

While a specific embodiment of the invention has been described, it is obvious that it is capable of considerable modification, and it is therefore not desired to limit the invention otherwise than as set forth in the appended claims.

Having thus described my invention what I claim and desire to protect by Letters Patent is: a

1. The method of finishing vulcanizable articles which comprises coating a rubber article .with a varnish comprising an oxidizable oil, and both heat curing, and subjecting the coated article to a superficial treatment with a medium containing a low concentration of a halogen-supplying material.

articles which comprises coating a rubber article with a varnish comprising an oxidizable oil, and both heat curing, and subjecting the coated article to a superficial treatment with a sulphur chloride in a circulating medium. 3. The method of finishing vulcanizable 'quently can be immediatel packed after the lUS' 100 also meets the requirements of those portions of the trade which demand that'goods even ment with a circulating medium containing a low concentration of a sulphur chloride.

5. The method of finishing vulcanizable articles which comprises coating a rubber article with a varnish comprising a boiled drying oil, and both heat curing, and subjecting the coated article to a superficial trgatment with diluted sulphur monochl'or1 e.

6; The method of finishing vulcanizable articles which comprises coating a rubber footwear article with a varnish comprising boiled linseed oil and sulphur, and both heat curing and superficially treating the coated article with a circulating aseous medium containing a low concentration of a sulphur chloride.

7. The method of finishing vulcanizable articles which comprises coatin a rubber footwear article with a varnish comprising an oxidizable oil, vulcanizing, then sub'ecting the coated article to a limited super cial treatment with agaseous fluid containin a low concentration of a halogen-supplying material, and neutralizing excess of the treating agent.

8. he method of finishing vulcanizable articles which comprises coating a rubber footwear article with a varnish comprising a drying oil and sulphur, vulcanizin then subjecting the coated article 'to a i-mited su erficial treatment with the vapor of a su (phur chloride diluted with an inert gas,

neutralizing the excess sulphur chloride with a base. v

9 The method of finishing vulcanizable articles which comprises coating 2. rubber footwear article with a. varnish comprising lmseed oil and sulphur, vulcanizing, and then first sub e'cting the article to a circulatmg gaseous current containing a low concentratlon of a halogen-supplying material all; then to a gaseous current containing a The method of finishing vulcanizable I articles which com rises coating a rubber footwear article wit a varnish comprising boiled linseed oil and sulphur, vulcanizin and then first subjecting the coated articia to' a circulating gaseous current containing ,a low concentration of sulphur monochloride 36 ammonia.

and then to a gaseous current containing 11. The method of finishing rubber footwear articles which have been varnished and then vulcanized which comprises giving them a hardened, non-tacky and wear-resisting surface by a mild treatment with a sulphur chloride diluted with an inert gas, and subsequently neutralizing excess of said agent.

12. The method of finishing rubber footwear articles which have been oil-varnished and then vulcanized which comprises giving them a hardened, non-tacky and wear-resisting surface by treatment with sulphur monochloride Vapor diluted with an inert gas.

13. The method of finishing vulcanizable articles which comprises coating the rubber article with a varnish comprising an oxidizable oil and both heat curing and mildly treating the surface of the article with a halogensupplying material in gaseous form.

14. The method of finishing vulcanizable articles which comprises coating the rubber article with a varnish comprising an oxidizable oil and both heat 'curing and mildly treating the surface of the article with a diluted halogen-supplying material in gaseous form. Y

15. The method of finishing vulcanizable articles which comprises coating the rubber article with a varnish comprising an oxidizable oil and both heat curing and mildly treating the surface of the article with a circulating diluted halogen-supplying material in gaseous form. v

16. The method of finishing vulcanizable articles which comprises coating the rubber article with a varnish comprising an exidizable oil, and subjecting the surfa'ce of the article to a. circulatmggaseous current containing a low concentration of a halogen- I sugplyin material.

igne at New Haven, county of New Haven, and State of Connecticut, this tenth day of December, 1926. v

SEAPHES D. SHINKLE. 

